The present invention relates to replaceable electrodes for arc spray welding guns. Arc spray welding guns are used to deposit a metal coating on areas of high wear, such as bearing surfaces. The electrodes of the arc spray welding guns are subject to excessive wear due to heat and friction. They carry a large electrical current which is induced in a pair of metalizing wires. The electrodes are substantially tubular and serve as a guide to accurately position the wires. Two electrodes are arranged in a "V" pattern and are separated by a compressed air nozzle in the arc spray gun. The metalizing wires automatically advance through the electrodes until they contact each other beneath the air nozzle. When the wires make contact the electrical circuit is completed. This creates an intense heat which liquefies the metalizing wires. At the same time the compressed air forces the molten metal through a horn shaped shield on the bottom of the arc spray gun. This produces a uniform spray of molten globules which is then deposited directly on the surface to be plated.
The tips of the electrodes are exposed to constant high heat and friction from the wires. They are also made of copper so as to be a good electrical conductor. The high heat and friction cause the soft metal electrode tips to wear very quickly. The electrode tips when new have a sliding fit with the metalizing wires within them. As the inner wire guiding portions of the tips wear out-of-round, the wires are no longer accurately positioned. This results in intermittent contact and causes an uneven spray. Because of this, a typical arc spray gun will use ten electrodes in one day of operation. At forty dollars per electrode this understandably runs into considerable expense. The manufacturer offers the electrodes as a unit only. Since only the tip of the electrode wears out, it is very desirable to obtain an electrode with inexpensive replaceable tips.